In many places, groundwater levels are falling — especially in places like Rajasthan and Tamil Nadu, where alternate sources of water are scarce.

To add to this problem, in many places, rainfall patterns are changing, most probably because of the warming climate. Shown below is the hundred year rainfall of Madurai. Annual rain received started falling about 30 years ago, and has kept falling since then.

OK. So we have a big problem.

Is there a solution?

Absolutely.

Countries with much less rain than us, export water — namely, Israel.

So there is a solution available today.

How do they do it?

They treat their sewage to such an extent, that the quality becomes almost good as fresh water. They then use it to irrigate their crops through drip irrigation.

Many places in India have used traditional methods such as check dams, farm ponds and bunds to conserve their rainwater.

There are methods to prevent evaporation from ponds and lakes.

But do you see a problem in adopting this to the Indian context?

Collecting sewage, treating sewage, using pipes to take it to agricultural regions, using drips all cost money. Building check dams, farm ponds and bunds take labour and maintenance — it costs money. Today, farmers get the power to run their pumps for free. Ground water is free.

Cities routinely lose more than half their municipal water to leaks.

In my house, until we installed meters on each tap, we found we were hugely inefficient in our water. Ditto for our farm. We reduced pressure, arrested leaks and reduced the number of hours we watered our plants. This has helped bring down our water use by 40–80%.

Again, meters, people to monitor the meters and take action all cost money.

In cities, there is an additional problem – the water tanker mafia. Many of us pay substantial prices – about Rs. 1-1.5 per litre for “drinking water” and less for more substandard water. This lobby prevents progress because they rake in huge sums in supply. They exist because municipal supply is so bad. Municipal supply is bad because we pay too little for it and because believe we cannot question its functioning.

Both of these have to change, if we need to make progress.

We need an universal price for water. Universal in that all users must be charged. But all users need not be charged the same price. Until and unless we charge a price for water — all water and for all users — there is no solution for this.